Elevating mechanism for a mobile gun



A ril 23, 1957 Y P. 'J. M. R. DELALANDE 2,789,475

ELEVATING MECHANISM FOR A MOBILE GUN Filed April 11, 1955 United States Patent ELEVATING MECHANISM FOR A MOBILE GUN Paul Jean Marie Rene Delalande, Washington, D. C., assignor to Anstalt fiir die Entwicklung von Erfindungen und Gewerblichen Andwendungen Energa, Vaduz, Liechtenstein Application April 11, 1955, Serial No. 500,437

Claims priority, application Switzerland May 4, 1954 1 Claim. (Cl. 89-41) This invention relates to artillery equipment.

The elevatingmechanism of conventional artillery is generally placed in the plane of symmetry of the gun. But because of the resulting encumbrance and of the absence of a readily accessible point of supporton the mounting, it is sometimes necessary to shift the elevation mechanism to one side of the mounting. In this case the front end of the elevating screw rests against a support piece solid with the support member for the barrel trunnions.

As a result of this arrangement the support member to which the elevating screw is solidly coupled, is subjected to a torque, during firing; This torque may be incompatible with the mechanical strength of said support member. At rest, the, cradle carrying the barrel is approximately balanced on the trunnions, but at the end of the recoil the center of gravity of the recoiling mass is to the rear of the trunnions; the weight of the recoiling mass thus generates a couple tending to lower the breech. This couple is balanced by that resulting from the reaction of the trunnions support member on the elevating screw.

This arrangement has nevertheless been applied to naval guns. In this case however the support member subjected to stress is provided with heavy ribs in order to stiifen it and prevent its deformation. This expedient is not desirable in the case of equipment which must be easily transportable, and therefore must be light in weight having regard to its performance.

The present invention has the object of obviating the various above-recited disadvantages. The improvement forming the subject of this invention is applicable to artillery towed on wheels and provided, with an elevating mechanism outside the vertical plane passing through the longitudinal axis of the gun, the elevating mechanism comprising essentially a worm perpendicular to the axle carrying the traction wheels, the rotational movement of which worm drives the elevating mechanism of the gun through the medium of at least one transmission member.

According to this invention, oneof the ends of the worm is rigidly connected to said axle, to which it transmits the longitudinal stresses to which it is subjected.

As a result the thrust during firing normally taken by the trunnion support member on the worm side is, according to this invention, transmitted to the axle which is supported on the two trunnion support members of the equipment. This particular arrangement of the elevating mechanism replaces the torque acting on only one of the trunnion support members by a plane fiexion, and the stresses transmitted by the axle to the two trunnion support members are directed in the same plane.

According to one particular embodiment of this invention, the above mentioned worm and axle are connected by a two-part yoke, the two parts of which are fixed one on the other.

The end of the worm that is rigidly connected to the axle preferably has a part of greater diameter which is ice engaged and held in one of said yokes between two bearings. In this way the longitudinal traction stress acting on the worm is transmitted to the. axle through the medium of said yoke.

For rapid firing, the gun remains carried by its Wheels, and the stress applied to the elevation worm changes direction when the piece rebounds on its tires. It will therefore be seen that it is necessary to transmit to the axle both the positive thrusts and the negative thrusts tending to move the worm both forwards and backwards along its axis.

Other advantages and features of the invention will become apparent from the following description taken in conjunction with the accompanying -dr'awingswhich illustrate diagrammatically and byway of example the preferred embodiment thereof, and in-which:

Figure 1 shows diagrammatically a gun hauled on wheels, to which theinvention is applied;

Figure 2 is a detail view in elevation, partly in section;

Figure 3 is a section on the line 3-3 in Figure 2.

The equipment shown in Figure l is constituted by a barrel-cradle-breech assembly I mounted on a three-trail carriage 2, the whole equipment being towed on the wheels 3 adapted to be raised when the piece is in the firing position. The cradle is joined to the carriage through the medium of two lateral trunnion support members 4, each of which is formed by two parallel plates. The two support members 4 carry the trunnions 5 at their upper ends. The elevating arm 6, which determines the angular displacement of the gun is fixed on the end of one of the trunnions. The arm 6 cooperates with the elevating worm or screw 7 through the medium of the nut 7a (Figure 3). The screw '7 is driven by means of a crank 8 (Figure 2) and is held in a bearing 9 at one end and at the other in a two-part yoke 10 enclosing the axle 11. The axle 11 is guided in support bearings 12, which are carried by the two trunnion support members 4. Two rocking arms (not shown) carrying the wheels 3 are mounted at the ends of the axle ll. 1 The end of the elevating screw 7 is held longitudinally'by two bearings 13 and 14 housed in the y 1 10. Each of these bearings supports one of the two faces of a collar 15 provided on said screw 7.

By way of example, if the recoiling mas'syis 225 kg, and the center of gravity of the mass, at the end of the recoil, is 1 metre from the trunnions 5, the mass would be subjected to a couple of 225 kg. If, moreover, the lever arm of the screw 7 (i. e. the distance from the trunnion to the axis of the screw) is 0.15 metre, the \lever would be subjected during normal firing (that is to say with the carriage stable) to a stress of 225/ 0..15:l500 kg.

If in this case the elevating screw were supported on a stop solid with the outer plate of the trunnion support member 4, of 0.004 metre thickness and if the stop were situated at a distance of 0.06 metre from the surface, a torque of 1000 0.06=60 kg. would result. It will therefore be understood that, when subjected to this stress, the plate of the-flask could be deformed and even break under the influence of local torsional stresses.

On the other hand, according to the invention, the thrust of the screw is transmitted to the axle which is supported on the two trunnion support members 4, in the manner of a straight beam resting on two simple supports.

It is obvious that the invention has been described only by way of example and that without departing from its scope, various modifications may be made thereto.

What I claim is:

A mobile gun having a three-trail carriage, two parallel support members mounted on the carriage, a barrelcradle-breech assembly, a pair of trunnions for the as- I; sembly, supported by said support members, an axle with two wheels supported by said members, a two-part yoke enclosing said axle and rigidly connected to one of said members, an elevating screw rotatably attached to said yoke, a nut movable on said screw, an arm connecting said nut with one of said trunnions, and an axially free thrust-bearing member within the yoke between the end of the screw and the axle for transmitting axial thrust from the screw to the axle.

References Cited in the file of this patent UNITED STATES PATENTS 

